Author Gillian Warson had the poignant experience of reuniting Jewish-born Philene Polak with a member of the family who sheltered her from the Gestapo in Nazi-occupied Holland during the Second World War.

Neither had seen each other for more than 50 years since Philene walked out of the house, where she had hidden in an adapted cupboard for two years, to join the Resistance.

Dr Warson, who lives in Bicester, came across the story when researching a biography of Fred Kaan, a church minister and composer of hymns, who in 1942 was living in Zeist, a small town near Utrecht in 1942.

She said: "The family were staunch socialists and had quickly become involved in the Dutch Resistance after the German occupation. Their newly-built house was in a terrace opposite a small wood, which gave the three-storyed house a secluded feel."

The Kaans agreed to shelter a Jew after a Jewish family living nearby in the same row of houses was taken away and never seen again. Fred's father realised he could make a haven for one person by adapting a cupboard, and offered to shelter Philene, who was already working for the Resistance and was a friend of Hannie Schaft, whose life was the basis of the film The Girl with the Red Hair.

Although Philene was living with Hannie, the Gestapo knew the address and Philene needed a new safe house. She stayed with the Kaans for two and a half years, joining the family for meals and helping Fred and his brother with their homework. At night she often walked in the wood.

"Philene began to find life more and more claustrophobic and grew desperate to return to active Resistance work. In the end she decided to leave the relative safety of the Kaan's house and take her chances with her former colleagues. With only her overcoat and a small bag she slipped out into the night and made for the centre of Amsterdam. The Kaan family never heard from her again," said Gillian.

Hannie was shot by the Gestapo in 1944 and another friend died in Auschwitz. The Kaans assumed Philene suffered the same fate, but were not sure. After the war Fred Kaan came to England and trained as a minister with the Congregational Church (later United Reformed Church), becoming a hymn writer of international repute. Some of his works were published in Methodist Church and other church hymn books and also in Anglican hymn books.

Gillian, who has a hymnology degree from Sheffield University, began to research Fred's life for a projected biography. She "I wanted to find out what had happened to Philene. Had she perished like so many Jews in the war or had she survived," said Gillian, who has a degree in hymnology from Sheffield University. By using extensive records of Jewish communities Gillian discovered that Philene had not died, nor had she gone to Israel like so many after the war. Through a website dedicated to people who worked in the Resistance, Gillian was able to track Philene in America, The woman running the website gave her a book on the Resistance, in which a Philene was mentioned.

Eventually after further help and inquiries Gillian was given Philene's address in America where she was living in retirement in Maine, having worked for the United Nations. She had married and had a family.

Philene admitted she was the same person who had lodged with the Kaans and agreed to meet Fred and Gillian in Holland last year. Gillian said: "She was very friendly and gracious. But they did not fall into each other's arms. It must be remembered that Fred was at the time a boy and while families gave shelter to someone like Philene, it was understood on both sides that there was no obligation on either side to be firm friends or keep in touch."

She added: "And it was only part of Fred's life, although he often spoke publicly about his experiences, the wartime atrocities and social injustices."

Before the biography, Gillian had produced four books on local history and she also lectures on hymns for Oxford University's continuing education department, and teaches the piano and violin. She sings in the Immanuel Ground quire (choir) based in Warwick, which specialises in 18th and 19th-century church music, which is known as West Gallery music.

This is music that was played by bands of musicians in the days before church organs and was featured by Thomas Hardy in his novel Under the Greenwood Tree.

Healing the Nations, Fred Kaan, the Man and his Hymns, by Gillian Warson, is published by Stainer and Bell at £9.50.